+1 I'm another convert to this simple solution. I ended up using a small wad of fabric cotton and while the miss is still "there" i actually find myself riding in the dreaded rpm zone for hundreds of metres before i notice that the bike isn't as smooth as at other times. Unlike previously when you simply had to change up or down gear to get out of the rpm range.

and for the record the bike is has additional holes cut in the airbox, no airbox snorkels and staintunes.

I've a strong feeling that an unmodified airbox and snorkels will help too... will update that once i get around to fitting them.

UPDATE: I've just fitted an un-modified airbox lid and the two factory air snorkels. It did improve the situation further so now the dreaded miss is the smallest little bump in otherwise smooth power. for example by contrast it's smoother to ride at constant throttle between 3500 and 4000 than it is just above idle to 2000 (where you get lots of driveline shunt) for example, and for a twin that's pretty good.

I also noticed that without any changes to idle setting (throttle stop etc) i've picked up about 200 rpm at idle. So the air flow has changed at idle too... i'm guessing that to be more/better flow at idle on the expectation that the computer is running the same richness it always has, but my logic might be flawed.

Can you say if your air box has been opened up,when I picked up my 907 it already had the ultimap installed
and the air box opened but I noticed on reflection that when I installed a K&N it was slightly less snatchy
at 3 to 4000 revs!I wonder if this has lessoned the vacuum pulses?Cheers for sharing your diagnosis/head ach.